I have a Uni-Sonic Instruments System, Model EC 200-1 and T200-1-1-EP-N Serial No. 1841 (Date in service June 15, 1977). Broadcast frequency is 218 kHz. The vendor manual I have for this hardware is dated 1973.This application measures level of product and the voltage is inverted with zero reference point 14 ft from the mounting flange. The output signal is 0-5 VDC over 0-14 ft. My Operators report that the level alarms for this unit are actuating early, causing level of product in the vessel to be less than expected. I\'ve found very little other information onsite about operation of this equipment. Are you familar with this admittedly antiquated hardware, and if so, is it parts supported? Finally, Please advise

all equipment ever manufactured by Inventron can be repaired at the factory.734-513-7700Arthur W. Merkl,General Manager